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ANDREW C. HARTSOCK, F-DOUGLAS,. ILLI-OIS.

Leners Patent Nb. 80,171, and July 21, 1868.

IMPROVBD MILLSTONE-DRESS.

@the Stigeml referrer in in that etter'ntmt mit mating tart nf the same. Y

TO ALL WI-IOM IT MAY CONCERN: A

Be it knownthat I, ANDVREW C. HARTSOCK, of Douglas, ,in the county otlKnox, and' State'of Illinois, have invented a new land useful Improvement in Millstonc-Dress; and I do hereby declare the following to be full and correct description thereof, sniicient to enable those skilled in the art to which my invention appertains to fully understand and construct the same, reference being'had to the accompanying dravvings, which make part yof this specification, and in .which- Figure] is a plan of the face of the bed-stone.

Figure 2 is a plan oi the face of the runner.

Figure 3 is a plan of the central portion of the hed-stone.

Figure 4 is a cross-section of iig. 2, and

Figure 5 is a cross-section of tig. 1.

Like letters of reference indicate like parts in the several figures of the drawings.

In the operation of grinding grain in mills it is a proposition well settled by practice that the amount grou-nd is always in proportion to the area of grinding-surface and the number of cutting-edges employed for such p'urpose. Inthe ordinary dress ofmiilstones di`erent sizes of grinding-disks are used.l `The lesser size willof necessity have to be revolved more rapidly, in order to bring the same amount gf grinding-surfaces and cutting-edges in contact with the grain being ground, in the same length of time as would be in disks of greater diameters and less revolutions.

In mills having grinding-disks of small diameters', in order to lcarry out thisrproposition, the revolutions are so rapid that many had effects follow, such as heating the spindle and causing expansion of the same, necessitating constant care inradjusting the stones, and in 4'the heating of the grinding-disks themselves, causing much ofthe grain to escape. from between the stones or disks imperfectly ground, and all overheated, to the manifest injury of all the meal so ground.

In order to produce grndingdisks;ot` small'diameter, having the grinding capacity ot' those of a greater diameter, without any of the detects enumerated as belonging to mills of small diameter, is the object of this invention; and it consstsin so constructing the dress ofir the stone, that' it `causes the cutting and grinding of the grain to lie/done upon the edges and sides ot' peculiarlysforrned teeth, instead of upon plane surfaces and straight or circular cutting-edges, as in the ordinary method of millstone-dress.

A, in the drawings, represents the distributing-teeth, near the centre of the disk or stone, so formed that, as the grain is fed through the eye, it comes in contact'wth and is'distributed by them into the radial furrows Zz and circular furrews a. v i i B B are the grinding-teeth, placed in eirelescuneentric with the eye, and separated by radial furrows'b, and from the next concentric seriesby'furrovrs a. i i

a a are i`u\-ro\vs,'in circ-iemand concentrically related to cach other, the inner, or that having the smallest diameter, being the deepest, and each successive or larger yin diameteris less in depth.

t b are short radial furrows, 'that cut across the concentric rings, and separate such rings into teeth B, having sharp inclined cuttingetlge, formed by the angular direction at which furrow b is cut.

This furrow is, by the tooth in the next concentric ring, interrupted in its continuance, which causes the grain to be deilected and traverse the furrow a to thenext radial or cross-furrow b.

The two stones or grinding-disks are constructed in such manner that the teeth B of one disk fit into the furrow a of the other. v g

The construction of thisdress is such that the teeth oi' the inner or smaller circle have the same or nearly the same area of grinding-surface and extent of cutting-edges as the larger in diameter and greater in number of the next circle, by reason of their greater projection from the bottom of the furrow.

It will also be seen that the cutting-edges of the teeth are of such shape that, as the teeth in the two disks approach and pass, the cutting o' the grain is marie by what is termed a shear out, thus tending to keep the edges in condition longer, and doing more work with thesame power than in the ordinary dress of millstones.

I am aware that oo'ee-hullers and coffee-mills have had the teeth upon their scouring and grinding-surfaces in irregular or zigzag forni, andl in concentric circles, in order to obstruct the direct passage of the coffee-grains from the mill without a complete operation, the ierenee between such a. construction of grinding-surfaces and teeth and my improvement being` that theteeth all project alike from the bottom of the furrow or plane ofthe disk. Nor i's the cuttiug-ege of the teeth thesame as mine'. Y Y

In my improvement the teeth in the di'erent circles vary in projection, and have a. ditlereutform of cuttingedge, as the teeth on the two disks, when/in operation, have a. very different angle at which the cutting-edge is formed and comes in e'ontact with the grain, andthe difference in the size and area ofthe grinding-surfaces of the teeth in different circles or" the several series. I

Having thus described my invention, and the difference 'between it and other inventions in like machines, what I claim as new, aud desire to secure by Letters Patent, is

The millstone-dress, composed of the distributing-teethA, grinding-teeth B, circle-furrows a, and'short angular furrows b, constructedand arranged iu relation to eachother, in the 'ma-nner and for the purpose substantially as described. Y

To the above ,I have signed my name, this 26th day of May, 1868.

I A. C. HARTSOCK.

Witnesses JOHN A. WIEDERSHEIM, l Cuirs.V D. SMITH. 1 

